Term I Exam Revision Test Paper 3 Class XII Subject Physics
Time 1.5 hr Multiple Choice Questions Dated: 06.12.2021 MM 35
Instructions: 1.Question paper has 35 multiple choice questions carrying 1 mark each.
2. Each question is compulsory.
Multiple Choice Questions:
1. Potential at any point inside a charged hollow sphere:
- (a) Increases with distance
- (b) is a constant
- (c) Decreases with distance from center
- (d) is zero
2. Charging without actual contact is called:
- (a) Charging by friction
- (b) Charging by conduction
- (c) Charging by induction
- (d) none of above
3. The drift velocity of the electrons is of the order of:
- (a) 10⁻³ms⁻¹or 10⁻⁴ ms⁻¹
- (b) speed of sound in vacuum
- (c) speed of light in vacuum
- (d) so fast that cannot be calculated
4. Specific resistance of a conductor increases with:
- (a) Increase in temp.
- (b) increase in area of cross section
- (c) decrease in length
- (d) decrease in area of cross section
5. The ultimate individual unit of magnetism in any magnet is called:
- (a) North pole
- (b) South pole
- (c) magnetic dipole
- (d) Quadrupole
6. A charged particle moving in a magnetic field experiences a resultant force:
- (a) In the direction of field
- (b) In the direction opposite to the field
- (c) In the direction perpendicular to both the field and its velocity
- (d) None of the above
7. In an ac series circuit, the instantaneous current is maximum when the instantaneous voltage is maximum. The circuit element connected to the source is:
- (a) Pure resistor
- (b) pure inductor
- (c) pure capacitor
- (d) none of these
8. The equivalent quantity of inertia in electricity is:
- (a) Current
- (b) self-inductance
- (c) potential
- (d) charge
9. Electromagnetic waves are transverse in nature is evident by
- (a) Polarization
- (b) Interference
- (c) Reflection
- (d) Diffraction
10. The velocity of electromagnetic wave is parallel to
- (a) 𝐵⃗ × 𝐸⃗
- (b) 𝐸⃗ × 𝐵⃗
- (c) 𝐸⃗
- (d) 𝐵⃗
11. The speed of electromagnetic wave in a medium of dielectric constant 2.25 and relative permeability 4 is
- (a) 1 x 10⁸ m/ s
- (b) 2.5 x 10⁸ m/ s
- (c) 2 x 10⁸ m/ s
- (d) 3 x 10⁸ m/ s
12. If a coil of metal is kept stationary in a non-uniform but constant magnetic field, then
- (a) An emf is induced in the coil
- (b) A current is induced in the coil
- (c) Neither emf nor current is induced
- (d) Both emf and current is induced
13. The induced emf in a coil is proportional to
- (a) Magnetic flux through the coil
- (b) Area of the coil
- (c) Rate of change of magnetic flux through the coil
- (d) Product of magnetic flux and area of the coil
14. In a circuit, current lags behind the voltage by a phase angle of π/2 or time T/2. The circuit contains which of the following?
- (a) Only R
- (b) Only C
- (c) Only L
- (d) R and C
15. A step-up transformer is used on a 120 V line to provide a potential difference of 2400 V. If the primary coil has 75 turns, the number of turns in the secondary coil is
- (a) 150
- (b) 1500
- (c) 1200
- (d) 1575
16. To shield an instrument from external magnetic field, it is placed in a cabin made of
- (a) Wood
- (b) iron
- (c) ebonite
- (d) diamagnetic substance
17. A charged particle enters at 30° to the magnetic field. Its path becomes:
- (a) Circular
- (b) elliptical
- (c) helical
- (d) straight line
18. The unit of electric field is not equivalent to
- (a) 𝑁/𝐶
- (b) 𝐽/𝐶
- (c) 𝑉/𝑚
- (d) 𝐽/𝐶𝑚
19. If the surface charge density of charged conductor be σ, electric field near the surface would be:
- (a)2𝜎/𝜀ₒ
- (b) 3𝜎/ 2𝜀ₒ
- (c)𝜎/2𝜀ₒ
- (d) 𝜎/𝜀ₒ
20. Work done in moving a unit positive charge through a distance of x meter on an equipotential surface is
- (a) x joule
- (b) 1/ x joule
- (c) zero
- (d) x²joule
21. The electric field at a point at far off distance r from the center of electric dipole lying on the axial line is proportional to
- (a) 1/𝑟
- (b) 1/𝑟²
- (c)1/𝑟³
- (d) 1/𝑟⁴
22. When a wire is stretched and its radius becomes 𝑟/2, then its resistance will be:
- (a) 16 R
- (b) 4 R
- (c) 2 R
- (d) 𝑅/2
23. Kirchhoff's rules I and II prove the law of
- (a) Conservation of charge and energy
- (b) Conservation of current and energy
- (c) Conservation of mass and charge
- (d) Conservation of mass and energy
24. A magnetic field can be produced by
- (a) A stationary charge
- (b) change in electric field
- (c) none of these
- (d) both (a) and (b)
25. No force is exerted by magnetic field on a stationary
- (a) Electric dipole
- (b) magnetic dipole
- (c) current loop
- (d) current carrying conductor
26. In a charged capacitor, the energy resides
- (a) On the positive plate
- (b) On both the positive & negative charged plates
- (c) In the field between the plates
- (d) Around the edge of the capacitor plates
27. What is the angle between the electric dipole moment and the electric field strength due to it on the equatorial line?
- (a) 0°
- (b) 90°
- (c) 180°
- (d) 270°
28. An electric dipole with the dipole moment 4 x 10⁻⁹⁴ Cm is aligned at an angle 30° with thedirection of uniform electric field of magnitude 5 x 10⁴ N/ C. The magnitude of the torque acting on the electric dipole is
- (a) 1 x 10⁻⁴Nm
- (b) 2 x 10⁻⁴ Nm
- (c) 4 x 10⁻⁴ Nm
- (d) 3 x 10⁻⁴ Nm
29. The no. of electric lines of force radiating from a closed surface in vacuum is 1.13 x 10¹¹.The charge enclosed by the surface is:
- (a) 1C
- (b) 1μC
- (c) 0.1 C
- (d) 0.1 μC
30. Sensitivity of potentiometer can be increase by
- (a) Increasing the emf of the cell
- (b) Increasing the length of the potentiometer wire
- (c) Deceasing the length of the potentiometer wire
- (d) None of the above
31. A wire has a resistance of 10.5 Ω at 21°C and 16.4Ω at 147°C. The value of temperature coefficient of resistance is
- (a) 0.0435°C⁻¹
- (b) 0.00525°C⁻¹
- (c) 0.00446°C⁻¹
- (d) 0.002871°C⁻¹
32. When an electron comes out of a region undeviated with the same speed (as at the time of entrance) where electric and magnetic fields are applied in the directions ⊥ to each other as well as to the velocity of electron, then the velocity of electron will be :
- (a) v = E× B
- (b) v = E÷ B
- (c) v = E+ B
- (d) v = E- B
33. A charge q is moving in a magnetic field, and then the magnetic force does not depend upon
- (a) Charge
- (b) mass
- (c) velocity
- (d) magnetic field
34. A galvanometer of resistance 15 Ω gives a full scale deflection of current of 2mA. The shunt resistance needed to convert it into an ammeter of range 0.5 A is
- (a) 0.0602 Ω
- (b) 0.00782Ω
- (c) 0.0020 Ω
- (d) 1.022Ω
35. An electron moving with a speed of 108 m/ s enters a magnetic field of 5 x 10-3 Tin a direction of perpendicular to field. Then the radius of the path will be (mass of electron = 9.1 × 10-31Kg, charge of electron = 1.6 × 10-19C)
- (a) 1.2 m
- (b) 0.43 m
- (c) 0.113 m
- (d) 0.54 m
